Potentiometric sensors based on anionic boron clusters

Abstract

Potentiometric sensor comprising an ion selective electrode and the latter, on its part, containing a membrane characterized in that it comprises: a thermoplastic material; an electroactive substance based on a salt wherein the cation is the protonated form of the analyte to be determined and the anion is a cluster which comprises boron atoms; and a plasticizing agent. In addition, the invention further relates to the use of said sensor for the detection and/or quantification of a compound containing at least one nitrogen atom.

The invention claimed is: 
     
       1. A membrane for a potentiometric sensor, comprising:
 a thermoplastic material, 
 an electroactive substance based on a salt wherein the cation is the protonated form of the analyte to be determined and the anion is a cluster which comprises boron atoms; and 
 a plasticizing agent. 
 
     
     
       2. The membrane according to  claim 1 , wherein the anion is mono- or polyanionic. 
     
     
       3. The membrane according to  claim 1 , wherein the boron cluster is selected from a list comprising a borane, a carborane or a metallocarborane. 
     
     
       4. The membrane according to  claim 3 , wherein the borate has the formula (B n H n ) 2− , (B n X m H n-m ) 2−  or (LB n H n ) − , wherein:
 n has a value between 6 and 12. 
 X is selected from a list that comprises hydrogen (H), halogen, an alkyl group or an aryl group, 
 m is a value between 0 and 12, 
 L is a XR′R″R′″ or XR′R″ group, where X is an N, P, S or O atom and R′, R″ and R′″ are radicals; equal or different, selected among, one atom of H, one alkyl group or one aryl group. 
 
     
     
       5. The membrane according to  claim 3 , wherein the carborane has the formula (RCB n H n ) −  or (RCB n X m H n-m ) − , wherein:
 R is H, an alkyl group or an aryl group, 
 n has a value between 5 and 11, 
 X is a halogen, an alkyl group or an aryl group, and 
 m has a value between 0 and 11. 
 
     
     
       6. The membrane according to  claim 3 , wherein the metallocarborane has the formula [M(C 2 B 9 H 11 ) 2 ] − , [M(C 2 B 9 H 11 ) 2 ] 2− , any of their derivatives or any mono- or di-ionic combination of at least two metallocarboranes, where M is a trivalent or divalent metal. 
     
     
       7. The membrane according to  claim 1 , wherein the thermoplastic material is polyvinylchloride (PVC). 
     
     
       8. The membrane according to  claim 1 , wherein the plasticizing agent is selected from a list comprising a polycarboxylic acid or any of its salts, benzoate, epoxydized vegetable oil, sulfonamide, organophosphate, polyether derived from glycol or any polymeric plasticizer derived from nitrobenzene. 
     
     
       9. The membrane according to  claim 8 , wherein the polycarboxylic acid is selected from a list comprising phthalic acid, adipic acid, sebacic acid or maleic acid. 
     
     
       10. An ion selective electrode (ISE), comprising a membrane according to  claim 1  on an electrical conductor or semiconductor support. 
     
     
       11. The ion selective electrode according to  claim 10 , wherein the support is graphite, any combination with graphite or an organic polymer. 
     
     
       12. A potentiometric sensor, comprising an ion selective electrode according to  claim 10  and a transducer. 
     
     
       13. A method for the detection and/or quantification of an analyte containing at least one nitrogen atom comprising using the potentiometric sensor according to  claim 12  or the ion selective electrode according to  claim 10 . 
     
     
       14. A method for the selective detection and/or quantification of enantiomers comprising using the potentiometric sensor according to  claim 12  or the ion selective electrode according to  claim 10 . 
     
     
       15. The method according to  claim 13 , wherein the detection is performed in biological fluids or other liquids—natural or synthetic. 
     
     
       16. The method according to  claim 14 , wherein the detection is performed in biological fluids or other liquids—natural or synthetic.